An X-wing aircraft is a rotary wing aircraft that uses a rigid rotor/wing utilizing circulation control airfoils. The rotor is driven mechanically and the rotor blades operate essentially in fixed pitch. The rotor may rotate, as in a helicopter, or it may be stopped and positioned so as to act like a fixed wing. Collective and cyclic control is achieved by control of air circulation about the blade airfoils. This is done by blowing compressed air through leading edge and trailing edge ducts in the rotor blades and modulating the amount of air being ejected through spanwise slots on the leading and trailing edges of the rotor blades.
The rotor system for an X-wing aircraft includes a hub and attached rotor blades and a pneumatic system for delivering compressed air separately to the leading edge and the trailing edge of the individual rotor blades at a desired pressure and mass flow. The pneumatic system includes a compressor, a stationary air supply to the rotor, valving for controlling the flow of air to the leading edge and the trailing edge of the blades, and a rotating air distribution arrangement. The system also includes a compressed, air storage chamber, or plenum, and it is the plenum which is the subject of this invention. A plenum chamber construction is described in copending application Ser. No. 431,475 filed Sept. 20, 1982.
A circulation control rotor system is described in the report titled "Circulation Control Rotor Flight Demonstrator" by David R. Barnes, Douglas G. Kirkpatrick and George A. McCoubrey presented at an American Helicopter Society Mideast Region Symposium in August, 1976. The report titled "Status Report on Advanced Development Program Utilizing Circulation Control Rotor Technology" by Kenneth R. Reader, Douglas G. Kirkpatrick and Robert M. Williams, Paper No. 44 presented at the Fourth European Rotorcraft and Powered Lift Aircraft Forum, Stresa, Italy, September 13-15, 1978 describes an X-wing development program.
Davidson et al U.S. Pat. No. 3,139,936 and Flint et al U.S. Pat. Nos. 3,348,618 and 3,349,853 describe a control mechanism for a helicopter having circulation control with compressed air being supplied through the rotor pillar. Cheeseman et al U.S. Pat. No. 3,524,711 and Seed U.S. Pat. No. 3,567,332 describe helicopter rotors employing circulation control.